Running rear wheel bearings in diff oil.

[BILT4ME]

The other thing that must be taken into consideration if you choose to pack your wheel bearings with grease: The wheel bearing grease MUST be compatible with the gear oil used.

There are certain types of greases and oils that are NOT compatible with each other. They will turn to cottage cheese and clump up and not lubricate anything because they don;t like each other. In the case of the rear wheel bearings, it is not a case of "if" it is a case of "when" they will mix.

 

[White Stripe]

Yea but that has happened to me with the axle seals in... so meh...

That should only happen though if the inner seal has failed.

 

[BILT4ME]

That should only happen though if the inner seal has failed.

And if you've ever personally installed one of those seals, you'll full appreciate why it fails in about 2 miles.

 

[LandCruiserPhil]

And if you've ever personally installed one of those seals, you'll full appreciate why it fails in about 2 miles.

▲this▲

 

[RFB]

Nope, not sarcasm. Hard wheeling, big tires and lots of miles means I chew through bearings about as fast as our austrailian friend. This is an interesting solution that is so simple I can't believe I didn't think about it sooner.


You could still do that without the seal... (I don't think I've seen a broken 80 series rear axle shaft that wasn't just straight abused on, like I'm talking ignorant levels of thrashing)

@OTRAMM truned me on to it a couple years ago. its legit

 

[shocktower]

I disagree with your one statement of:
"* service is easier since replacing the lube in the hub bearings will happen when I drain/refill the center diff"

The oil in the wheel bearings will NOT be replaced when you drain and refill the differential. There is NO drain or flow bypass for the oil from the spindle to return to the differential. Once the oil has flowed outward into the wheel bearings, it is there until it leaks out of the hub seal. Yes, there will be a SMALL amount of mixing at the tip of the spindle, but it will NOT be "refreshed" just by doing a differential oil drain.

Otherwise, it does not appear to be harmful to run them in gear oil, as all the Dana 60+ full float rear axles on Chevy, Dodge, Ford all run gear oil in the wheel bearings.

But when you go off cambers or side hills Mountains , it does cycle the oil, unless you live in the midwest , and there is not much mountains or off cambers

 

[shocktower]

Keep in mind too that if the wheel seal goes bad on the hub then gear oil will get flung all over the brake shoes and pads. Not saying running the bearings on gear oil is bad, just listing the cons. I dont see anyone else doing that. Everything has pros n cons.

I have been running an oil bath for more than a 80K miles and no oil or failed hub seal just axle seal is crap, I do have new ones

 

[Tools R Us]

It's not that scary, really it's not! The one we are doing in the morning, is stock, leaking at the hub seal, so both seals failed. It leaks out the rotor cooling fin area, isn't on the pads, the only problems, makes a mess and stinks when the brakes are used a lot. It just returned from a trip to Death Valley, so lots of miles, made it home.

Many have been run on oil, without the inner seal, long term, without issue, not a new concept.

 

[-Spike-]

But when you go off cambers or side hills Mountains , it does cycle the oil, unless you live in the midwest , and there is not much mountains or off cambers

Or when you, like, turn and stuff.

 

[BILT4ME]

But when you go off cambers or side hills Mountains , it does cycle the oil, unless you live in the midwest , and there is not much mountains or off cambers

When you set a 2 liter full of water, upside down in a dish, the water will rise in the dish to meet the bottom of the nozzle. The water from the dish cannot run back Up into the bottle.

When your hub fills with oil, then you tip the truck on its side to drain the diff oil to the spindle / hub. How will the oil already in the hub be refreshed? Unless the hub is already leaking plenty and the level is low?

Sidehills, corners, and ditches will allow oil to run from the center diff to the outer hub. Even in the state as flat as Kansas.........

 

[shocktower]

When you set a 2 liter full of water, upside down in a dish, the water will rise in the dish to meet the bottom of the nozzle. The water from the dish cannot run back Up into the bottle.

When your hub fills with oil, then you tip the truck on its side to drain the diff oil to the spindle / hub. How will the oil already in the hub be refreshed? Unless the hub is already leaking plenty and the level is low?

Sidehills, corners, and ditches will allow oil to run from the center diff to the outer hub. Even in the state as flat as Kansas.........

Like I said I am a FNG just learning, Oh yeah there is a vent on the pumpkin and that way the oil goes back, since the 2 liter bottle doesn't have a vent this is vapor lock and does not allow it, but since I'm new at this I am still trying

 

[mudgudgeon]

My concern would be if you ever have to run without axle shafts because you broke something offroad. The benefit of grease is you can run without a axle shaft. If you broke a axle shaft and were worried about shrapnel in the differential moving around and killing the 3rd member, with grease you can just pull the drive shaft and axle shafts, and drive out in front wheel drive.

In the scenario what do you think happens to all the gear oil with the axle out?

 

[sunrk]

My 80 is part-time 4wd not full-time, so I don't know if this will work, but if you were not using grease-packed rear hubs and opted to run without inner axle seals and run diff oil for lube in rear hub bearings, can full-time 4wd drive flanges be bolted in place of the 'drive flange' of a rear axle shaft in order to 'seal up' the rear hub(s) if the rear axle shafts needed to be removed? i have never actually compared to see if an Aisin hub body has the same bolt/stud diameter as the rear axle drive flanges. Front axle drive flanges for full-time 4wd 80's should be very common. Just a suggestion in case it might be possible.

 

[Tools R Us]

The bolt pattern is the same, some carry a spare drive flange. I have never seen a broken FF axle.

 

[SmokingRocks]

I have never seen a broken FF axle.

Sums it up perfectly. If it ain’t broke don’t dick with it.

 

[Track Rat]

It's not that scary, really it's not! The one we are doing in the morning, is stock, leaking at the hub seal, so both seals failed. It leaks out the rotor cooling fin area, isn't on the pads, the only problems, makes a mess and stinks when the brakes are used a lot. It just returned from a trip to Death Valley, so lots of miles, made it home.

Many have been run on oil, without the inner seal, long term, without issue, not a new concept.

I switched rear bearings to oil about 2,500 miles ago; no leaks and everything's still tight. I really like to use of cap screws too as the cone washers dont require a brass drift to coax them out. Replaced the front studs with cap screws too.

 

[-Spike-]

I really like to use of cap screws too as the cone washers dont require a brass drift to coax them out. Replaced the front studs with cap screws too.

My concern with deleting the cone washers is that now you are relying primarily on the pins to prevent the axle flange from moving around axially, along with some compression force from the bolts. With cones, all the slack is completely removed, and the flange is locked in place in eight positions. Bolt shafts will not fit tightly in the axle flange holes, so some slop could develop, hypothetically. That being said, I know a few people that run (oversized) bolts sans cone washers with no issues.

For me, having had a lot of practice, the cone washers aren't difficult at all to remove. I do have spare studs in case I damage one, but it hasn't happened yet.

Or, am I misunderstanding you? Are you using cap screws with the cone washers? That would be interesting. I'm not sure if the cone washers would torque down as tightly if the bolt shaft is dragging on the inner surface of them.

 

[Fairgame]

Without the seal? How would that work? Im thinking if the axle shaft is not in the hub, the bearings will not get any oil from the axle housing, whatever oil is in the hub will get flung out after a short time and become starved of lube since the shaft caps the end of the spindle. Not saying it would be a common need to run without a axle shaft, but just a benefit of having grease over oil. Axle shafts fatigue over time similar to a sway bar from lots or torsional cycles. Once a shaft is fatigued it can break easily. Pinions can do this too.

Never come across a broken shaft. In the safari business, we change out the wheel bearings and oils every two years. Clean and grease every season. It's a small service and well worth doing for peace of mind especially when working in remote areas. Same with prop shafts which are further protected with a rubber sleeve.

 

[White Stripe]

Never come across a broken shaft. In the safari business, we change out the wheel bearings and oils every two years. Clean and grease every season. It's a small service and well worth doing for peace of mind especially when working in remote areas. Same with prop shafts which are further protected with a rubber sleeve.

I put a 80 series rear axle in the rear of my fj40 a few years ago. I broke a left rear axle shaft last year. My fj40 has 35" tires and a 2f engine. I used to run cheap aftermarket u-joints so that the ujoints were the weak link. I replaced the ujoints with factory ones and now I guess the axle shafts are the weak link. I was trying to crawl up a rock and I was more bound up than I thought. The scenario of running without the shafts in the hub would be if I damaged the differential somehow. I've never damaged the differential on this axle so far.

 

[Broski]

I’m running the OEM seals with out issues, hard wheeling on 39s
I like the idea that if I sheer the hub bolts, damage the third or brake a axle I can drive off the trail having the bearings greased.